1. #define F_CPU 16000000UL
  3. #include <avr/io.h>
  5. #include <avr/interrupt.h>
  7. /******************************************************************************/
  9. int main(void)
  10. {
  11. cli();
  13. DDRD &= ~_BV(DDD0); // set as input
  14. PORTD |= _BV(PORTD0); // enable pull-up
  16. DDRB |= _BV(DDB5);
  17. PORTB |= _BV(PINB5); // initialize to high
  19. #if 0
  20. PCICR |= _BV(PCIE2); // set PCIE2 to enable PCMSK2 scan
  21. PCMSK2 |= _BV(PCINT16); // set PCINT16 to trigger an interrupt on state change
  22. #endif
  24. sei(); // turn on interrupts
  26. while (1) asm volatile ("nop"::);
  27. }
  29. /******************************************************************************/
  31. ISR (PCINT1_vect) {}
  33. /******************************************************************************/